Extend SCMI protocols accounting to address possible module usage and add
the support to possibly define new protocols as loadable modules.
Keep Standard protocols built into the SCMI core.
Signed-off-by: Cristian Marussi <cristian.maru...@arm.com>
---
drivers/firmware/arm_scmi/base.c | 2 ++
drivers/firmware/arm_scmi/bus.c | 11 ++++++++++-
drivers/firmware/arm_scmi/clock.c | 2 ++
drivers/firmware/arm_scmi/common.h | 4 ++++
drivers/firmware/arm_scmi/driver.c | 5 ++++-
drivers/firmware/arm_scmi/perf.c | 2 ++
drivers/firmware/arm_scmi/power.c | 2 ++
drivers/firmware/arm_scmi/reset.c | 2 ++
drivers/firmware/arm_scmi/sensors.c | 2 ++
drivers/firmware/arm_scmi/system.c | 2 ++
include/linux/scmi_protocol.h | 12 ++++++++++++
11 files changed, 44 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index 745e475e6cc4..e66e23d07d82 100644
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -7,6 +7,7 @@
#define pr_fmt(fmt) "SCMI Notifications BASE - " fmt
+#include <linux/module.h>
#include <linux/scmi_protocol.h>
#include "common.h"
@@ -373,6 +374,7 @@ static int scmi_base_protocol_init(const struct
scmi_protocol_handle *ph)
static const struct scmi_protocol scmi_base = {
.id = SCMI_PROTOCOL_BASE,
+ .owner = NULL,
.init = &scmi_base_protocol_init,
.ops = NULL,
.events = &base_protocol_events,
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 25b191cfefc1..b152860f6c99 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -56,7 +56,7 @@ const struct scmi_protocol *scmi_get_protocol(int protocol_id)
const struct scmi_protocol *proto;
proto = idr_find(&scmi_available_protocols, protocol_id);
- if (!proto) {
+ if (!proto || !try_module_get(proto->owner)) {
pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id);
return NULL;
}
@@ -66,6 +66,15 @@ const struct scmi_protocol *scmi_get_protocol(int
protocol_id)
return proto;
}
+void scmi_put_protocol(int protocol_id)
+{
+ const struct scmi_protocol *proto;
+
+ proto = idr_find(&scmi_available_protocols, protocol_id);
+ if (proto)
+ module_put(proto->owner);
+}
+
static int scmi_dev_probe(struct device *dev)
{
struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
diff --git a/drivers/firmware/arm_scmi/clock.c
b/drivers/firmware/arm_scmi/clock.c
index 00041dcb4d06..06ed45c0002a 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -5,6 +5,7 @@
* Copyright (C) 2018-2020 ARM Ltd.
*/
+#include <linux/module.h>
#include <linux/sort.h>
#include "common.h"
@@ -367,6 +368,7 @@ static int scmi_clock_protocol_init(const struct
scmi_protocol_handle *ph)
static const struct scmi_protocol scmi_clock = {
.id = SCMI_PROTOCOL_CLOCK,
+ .owner = THIS_MODULE,
.init = &scmi_clock_protocol_init,
.ops = &clk_ops,
};
diff --git a/drivers/firmware/arm_scmi/common.h
b/drivers/firmware/arm_scmi/common.h
index 9ae0e4133f31..d3f62f85ea18 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -14,6 +14,7 @@
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/scmi_protocol.h>
#include <linux/types.h>
@@ -216,6 +217,7 @@ typedef int (*scmi_prot_init_fn_t)(const struct
scmi_protocol_handle *);
/**
* struct scmi_protocol - Protocol descriptor
* @id: Protocol ID.
+ * @owner: Module reference if any.
* @init: Mandatory protocol initialization function.
* @deinit: Optional protocol de-initialization function.
* @ops: Optional reference to the operations provided by the protocol and
@@ -224,6 +226,7 @@ typedef int (*scmi_prot_init_fn_t)(const struct
scmi_protocol_handle *);
*/
struct scmi_protocol {
const u8 id;
+ struct module *owner;
const scmi_prot_init_fn_t init;
const scmi_prot_init_fn_t deinit;
const void *ops;
@@ -256,6 +259,7 @@ void __exit scmi_##name##_unregister(void) \
}
const struct scmi_protocol *scmi_get_protocol(int protocol_id);
+void scmi_put_protocol(int protocol_id);
int scmi_acquire_protocol(const struct scmi_handle *handle, u8 protocol_id);
void scmi_release_protocol(const struct scmi_handle *handle, u8 protocol_id);
diff --git a/drivers/firmware/arm_scmi/driver.c
b/drivers/firmware/arm_scmi/driver.c
index d6a975992136..077152fd5fc3 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -677,7 +677,7 @@ scmi_get_protocol_instance(const struct scmi_handle
*handle, u8 protocol_id)
/* Fail if protocol not registered on bus */
proto = scmi_get_protocol(protocol_id);
if (!proto) {
- ret = -ENODEV;
+ ret = -EPROBE_DEFER;
goto out;
}
@@ -722,6 +722,7 @@ scmi_get_protocol_instance(const struct scmi_handle
*handle, u8 protocol_id)
return pi;
clean:
+ scmi_put_protocol(protocol_id);
devres_release_group(handle->dev, gid);
out:
mutex_unlock(&info->protocols_mtx);
@@ -772,6 +773,8 @@ void scmi_release_protocol(const struct scmi_handle
*handle, u8 protocol_id)
idr_remove(&info->protocols, protocol_id);
+ scmi_put_protocol(protocol_id);
+
devres_release_group(handle->dev, gid);
dev_dbg(handle->dev, "De-Initialized protocol: 0x%X\n",
protocol_id);
diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
index c1d0664aaf4a..66e0d2364ea6 100644
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -11,6 +11,7 @@
#include <linux/of.h>
#include <linux/io.h>
#include <linux/io-64-nonatomic-hi-lo.h>
+#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/scmi_protocol.h>
@@ -900,6 +901,7 @@ static int scmi_perf_protocol_init(const struct
scmi_protocol_handle *ph)
static const struct scmi_protocol scmi_perf = {
.id = SCMI_PROTOCOL_PERF,
+ .owner = THIS_MODULE,
.init = &scmi_perf_protocol_init,
.ops = &perf_ops,
.events = &perf_protocol_events,
diff --git a/drivers/firmware/arm_scmi/power.c
b/drivers/firmware/arm_scmi/power.c
index d9ce794d0299..819d948eb034 100644
--- a/drivers/firmware/arm_scmi/power.c
+++ b/drivers/firmware/arm_scmi/power.c
@@ -7,6 +7,7 @@
#define pr_fmt(fmt) "SCMI Notifications POWER - " fmt
+#include <linux/module.h>
#include <linux/scmi_protocol.h>
#include "common.h"
@@ -310,6 +311,7 @@ static int scmi_power_protocol_init(const struct
scmi_protocol_handle *ph)
static const struct scmi_protocol scmi_power = {
.id = SCMI_PROTOCOL_POWER,
+ .owner = THIS_MODULE,
.init = &scmi_power_protocol_init,
.ops = &power_ops,
.events = &power_protocol_events,
diff --git a/drivers/firmware/arm_scmi/reset.c
b/drivers/firmware/arm_scmi/reset.c
index a183518baf18..9f408070b70d 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -7,6 +7,7 @@
#define pr_fmt(fmt) "SCMI Notifications RESET - " fmt
+#include <linux/module.h>
#include <linux/scmi_protocol.h>
#include "common.h"
@@ -324,6 +325,7 @@ static int scmi_reset_protocol_init(const struct
scmi_protocol_handle *ph)
static const struct scmi_protocol scmi_reset = {
.id = SCMI_PROTOCOL_RESET,
+ .owner = THIS_MODULE,
.init = &scmi_reset_protocol_init,
.ops = &reset_ops,
.events = &reset_protocol_events,
diff --git a/drivers/firmware/arm_scmi/sensors.c
b/drivers/firmware/arm_scmi/sensors.c
index a74a7938cd78..170d97f09d91 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -7,6 +7,7 @@
#define pr_fmt(fmt) "SCMI Notifications SENSOR - " fmt
+#include <linux/module.h>
#include <linux/scmi_protocol.h>
#include "common.h"
@@ -375,6 +376,7 @@ static int scmi_sensors_protocol_init(const struct
scmi_protocol_handle *ph)
static const struct scmi_protocol scmi_sensors = {
.id = SCMI_PROTOCOL_SENSOR,
+ .owner = THIS_MODULE,
.init = &scmi_sensors_protocol_init,
.ops = &sensor_ops,
.events = &sensor_protocol_events,
diff --git a/drivers/firmware/arm_scmi/system.c
b/drivers/firmware/arm_scmi/system.c
index 23365ef334bf..13bd223feb84 100644
--- a/drivers/firmware/arm_scmi/system.c
+++ b/drivers/firmware/arm_scmi/system.c
@@ -7,6 +7,7 @@
#define pr_fmt(fmt) "SCMI Notifications SYSTEM - " fmt
+#include <linux/module.h>
#include <linux/scmi_protocol.h>
#include "common.h"
@@ -129,6 +130,7 @@ static int scmi_system_protocol_init(const struct
scmi_protocol_handle *ph)
static const struct scmi_protocol scmi_system = {
.id = SCMI_PROTOCOL_SYSTEM,
+ .owner = THIS_MODULE,
.init = &scmi_system_protocol_init,
.ops = NULL,
.events = &system_protocol_events,
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 66625aedd3a7..7d6a12baa254 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -378,6 +378,18 @@ static inline void scmi_driver_unregister(struct
scmi_driver *driver) {}
#define module_scmi_driver(__scmi_driver) \
module_driver(__scmi_driver, scmi_register, scmi_unregister)
+/**
+ * module_scmi_protocol() - Helper macro for registering a scmi protocol
+ * @__scmi_protocol: scmi_protocol structure
+ *
+ * Helper macro for scmi drivers to set up proper module init / exit
+ * functions. Replaces module_init() and module_exit() and keeps people from
+ * printing pointless things to the kernel log when their driver is loaded.
+ */
+#define module_scmi_protocol(__scmi_protocol) \
+ module_driver(__scmi_protocol, \
+ scmi_protocol_register, scmi_protocol_unregister)
+
struct scmi_protocol;
int scmi_protocol_register(const struct scmi_protocol *proto);
void scmi_protocol_unregister(const struct scmi_protocol *proto);
--
2.17.1
